Board Foot Calculator
Calculate lumber volume in board feet and estimate costs for construction and woodworking projects
Calculate Board Feet
Choose calculation method based on your material type
How many lumber pieces you need
Length of the lumber piece
Width of the lumber piece
Thickness of the lumber piece
Enter lumber price to calculate total cost and cost per linear foot
Board Foot Results
Formula: Board Feet = Length (ft) × Width (in) × Thickness (in) ÷ 12
Calculation: 0.000 ft × 0.000" × 0.000" ÷ 12 = 0.000 BF per piece
Total: 0.000 BF × 1 pieces = 0.000 BF
Key conversions: 1 BF = 144 cubic inches = 1/12 cubic foot
Lumber Size Analysis
Example Calculations
Hardwood Deck Example
Project: Hardwood decking boards
Pieces needed: 25 boards
Dimensions: 8 feet × 5.5 inches × 1.5 inches
Price: $6.50 per board foot
Calculation
Board feet per piece = 8 ft × 5.5 in × 1.5 in ÷ 12
Board feet per piece = 66 ÷ 12 = 5.5 BF
Total board feet = 5.5 BF × 25 pieces = 137.5 BF
Total cost = 137.5 BF × $6.50 = $893.75
Cost per linear foot = $6.50 × 5.5 × 1.5 ÷ 12 = $4.48/ft
Log Scaling Example
Project: Oak logs for milling
Number of logs: 3
Diameter: 16 inches (small end, no bark)
Length: 12 feet each
Price: $3.25 per board foot
Doyle Rule Calculation
BF per log = ((16 - 4) ÷ 4)² × 12
BF per log = (12 ÷ 4)² × 12 = 3² × 12 = 108 BF
Total board feet = 108 BF × 3 logs = 324 BF
Total value = 324 BF × $3.25 = $1,053
Bulk Volume Conversion
Scenario: Lumber pile measurement
Total volume: 85 cubic feet
Price: $4.75 per board foot
Conversion
Board feet = 85 cubic feet × 12 BF/cubic foot
Board feet = 1,020 BF
Total value = 1,020 BF × $4.75 = $4,845
Common Lumber Sizes (Board Feet per Linear Foot)
2×4 Board Feet by Length
Unit Conversions
- • 144 cubic inches
- • 1/12 cubic foot (0.0833 cu ft)
- • 2,359.7 cubic cm
- • 0.002359 cubic meters
- • 2.36 liters
One board foot is the volume of a board that is 1 foot long, 1 foot wide, and 1 inch thick.
Doyle Rule is conservative but widely used. International 1/4" rule gives higher yields.
Wood Density (lbs per BF)
Lumber Tips
Always measure actual dimensions, not nominal sizes
Add 10-15% extra for waste and cuts
Consider lumber grade for your project needs
Check moisture content for indoor projects
Compare prices per board foot, not per piece
Understanding Board Feet Calculations
What is a Board Foot?
A board foot is a unit of measurement for lumber volume. Unlike square footage which measures area, board footage measures volume. One board foot equals the volume of a board that is 1 foot long, 1 foot wide, and 1 inch thick (144 cubic inches).
Standard Formula
Board Feet = Length (ft) × Width (in) × Thickness (in) ÷ 12
Why Use Board Feet?
- •Standard measurement for pricing lumber
- •Allows comparison of different sized boards
- •Helps estimate material costs accurately
- •Industry standard for hardwood lumber
Calculation Methods
Standard Lumber
For dimensional lumber and boards. Uses length in feet, width and thickness in inches.
Log Scaling (Doyle Rule)
For estimating board feet in logs: ((Diameter - 4) ÷ 4)² × Length. Conservative estimate commonly used in North America.
Bulk Volume
Convert known cubic footage to board feet. Useful for lumber piles or bulk measurements.
Important: Actual lumber dimensions differ from nominal sizes. A "2×4" is actually 1.5" × 3.5". Always use actual dimensions for accurate calculations.
Board Foot Applications
Construction Lumber
- • Framing materials
- • Structural beams
- • Dimensional lumber
- • Cost comparison
Hardwood & Woodworking
- • Furniture projects
- • Cabinet making
- • Flooring materials
- • Specialty wood purchases
Forestry & Logging
- • Log scaling
- • Timber sales
- • Forest inventory
- • Mill planning
Measurement Best Practices
Accuracy Tips
- ✓Always use actual dimensions, not nominal sizes
- ✓Measure to the nearest 1/8 inch for precision
- ✓Account for variations in lumber dimensions
- ✓Consider waste factor (typically 10-15%)
Cost Planning
- ✓Compare prices per board foot, not per piece
- ✓Factor in delivery costs for bulk orders
- ✓Consider lumber grade for project requirements
- ✓Check moisture content for indoor projects